U.S. Pat. No. 4,410,321 to Pearson, et al. is hereby incorporated by reference.
A large number of drugs are packaged in well known glass drug bottles having rubber-like pierceable rubber stoppers. These drugs are usually in powder, including crystalline, form. For delivery to a patient, the drug must be reconstituted. This is typically performed by piercing the stopper with a hollow stainless steel needle having a sharpened tip. The needle is secured to a syringe assembly of well known construction, including a cylindrical barrel and piston.
Typically, the needle is brought to a point on one side of the needle wall by a bevel structure so that the needle tip is quite sharp. Such needles are subject to coring. Coring is the collection of barrier material, in this case part of the stopper, inside the hollow needle tip. When liquid is pumped between the syringe and the drug vial for drug reconstitution, any stopper material in the needle tip caused by coring results in stopper particulate matter in the liquid.
Particulate matter may also be generated, although to a lesser degree, between the stopper and the outer wall of the needle as the needle passes through the stopper.
Such known needle structures are expensive to manufacture and may require swaging, grinding, buffing and sandblasting operations. Most stainless steel needles also generally require lubrication such as with silicone due to the non-slip characteristics of the stainless steel. Other needle structures are known which have a closed end but which employ openings in the sidewall of the needle. This may somewhat reduce coring but the needle interior is still open during piercing of a barrier.
After the drug is reconstituted in the liquid, which may be sterile water or sterile saline or dextrose solution, for example, the solution is withdrawn from the vial into the syringe for further injection, typically into a patient directly or into a solution container such as a VIAFLEX.RTM. container sold by Travenol Laboratories, Inc. of Deerfield, Ill. The VIAFLEX container may be connected to the patient's intravenous system by means of a parenteral solution administration set. If the reconstituted drug is to be injected into a solution container, a reconstitution device such as the vial and syringe connector assembly shown in U.S. Pat. No. 3,976,073 may be employed, in order to pierce an injection site on the solution container. The syringe connector assembly shown in U.S. Pat. No. 3,976,073 also includes a blunt end of the needle opposite from the pointed end, the blunt end being adapted for piercing a specially adapted diaphragm so as to form a flap in the diaphragm to reduce coring.
More recently, a closed drug delivery system utilizing a sterile coupling has been developed, as described in the above-mentioned U.S. Pat. No. 4,410,321, incorporated by reference herein. There, a needle mounted to a flexible, compressible chamber is also secured in pre-piercing relation to a standard drug vial by a junction means which may comprise a block of injection molded plastic around both the rubber stopper and the needle. To place the flexible chamber and the vial in fluid communication, the plastic junction, as well as the rubber stopper of the vial is pierced, thereby making coring and the generation of particulate matter a possibility with the plastic junction means as well as with the rubber stopper in the vial.
It would be desirable to employ a needle construction, both with the junction means and vial combination shown in U.S. Pat. No. 4.410,321, as well as with the rubber stopper of a standard drug vial, which both eliminates coring and reduces the generation of particulate matter.